Physics Formula Sheet

Physics Formulae & Equations (Compiled specially for CSEC students)

Formulae/Equations

Symbols & Units

Density, = ⁄ Relative Density, =

= density, kgm-3 = relative density, [dimensionless] = mass, kg = volume, m3

Moment or Torque is the rotational or turning effect that a force produces. =

= moment/torque, Nm Note that Moment or Torque is NOT Energy and cannot be used with the Joule (J). = force, N = distance (perpendicular fr. pivot to F), m

Hooke’s Law states that Force is proportional to the extension of spring or elastic material provided the elastic limit is not exceeded. ∝

= force, kgms-2 ≡ N or = displacement/extension, m

Newtonian Laws: 1st Law - The Law of Inertia 2nd Law - ∝ ( − ) =

= force, kgms-2 ≡ N = mass, kg = acceleration, ms-2 = (final) velocity, ms-1 = (initial) velocity, ms-1 = time, s = distance, m or = displacement, m

= 3rd Law - Action = Reaction . = = =

+ = 2 + × 2 + 1 + 2

Linear Momentum, = Conservation of Momentum, before = after Collision of A and B, + =( Repulsion of A and B, = Impulse,

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=

+

)

= momentum, kgms-1 Note that kgms-1 ≠ kgms-2 = mass, kg = mass of A, kg = mass of B, kg = (final) velocity, ms-1 = pre-collision velocity of A, ms-1 = pre-collision velocity of B, ms-1 = post-collision velocity of A, ms-1 = post-collision velocity of B, ms-1 = force, kgms-2 ≡ N = impulse, Ns ≡ kgms-1 = time, s

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Physics Formulae & Equations (Compiled specially for CSEC students)

Formulae/Equations

Symbols & Units

Energy Work,

= work, Nm ≡ J = force (in the dir. of motion), kgms-2 ≡ N = displacement, m = kinetic energy, J = (gravitational) potential energy, J = mass, kg = velocity, ms-1 = gravitational field strength, ms-2 ℎ = height, m = time, s

=

Kinetic Energy,

=

(Gravitational) Potential Energy, = ℎ Power,

=

Efficiency =

× 100

= [dimensionless] (can be expressed as solely as a number or a percentage when that number is multiplied by 100). = energy output, J = energy input, J

Pressure = = Δℎ (in fluids)

= pressure, Nm-2 ≡ Pa = area, m2 = density, kgm-3 = acceleration of free fall, ms-2 Δℎ = change in height, m

Archimedes Principle Upthrust (U)= True Weight of Body (W1) – Apparent Weight of Body (W2)

U = upthrust, N W = weight, N

Upthrust (U)= Apparent Weight Loss of Body (W) Upthrust (U)= Weight of Fluid displaced by Body (W) Gas Laws Boyle’s Law,

=

Charles’ Law,

=

Pressure Law,

=

= pressure, Nm-2 ≡ Pa = volume, m3 = temperature, K , , = constants

General Gas Law or Combined Gas Equation, =

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Physics Formulae & Equations (Compiled specially for CSEC students)

Formulae/Equations Heat Capacity,

=

= heat capacity, JK-1 = specific heat capacity, Jkg-1K-1 or = heat/thermal energy, J ∆ (delta theta)= change in temperature, K = specific latent heat of fusion, Jkg-1 = specific latent heat of vapourization, Jkg-1

Heat Energy, = ∆ = = Wave Formulae = = =1 , =1 Reflection,

=

Refraction, (Snell’s Law) =

=

=

Critical Angle – is the angle of incidence of a wave when the angle of refraction is 90º, = Lens Magnification =

( ) ( )

=

Electricity = = = = In Series: =

= = = = +

+

Symbols & Units

+. ..

= velocity, ms-1 = velocity of incident wave, ms-1 = velocity of refracted wave, ms-1 = time, s = period, s = frequency, s-1 ≡ Hz = distance, m = wavelength, m = wavelength of incident wave, m = wavelength of refracted wave, m = angle of incident wave, º = angle of reflection, º = angle of incidence, º = angle of refraction, º = critical angle, º = refractive index, [dimensionless] = refractive index of first medium, [dimensionless] = refractive index of second medium, [dimensionless]

= voltage/potential difference/ electromotive force (e.m.f.), V = current, A = resistance, Ω (Ohm) = power, Js-1 ≡ W = energy, J = time, s Q = quantity of charge, As ≡ C

In Parallel: 1 1 1 1 = + + +⋯

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Physics Formulae & Equations (Compiled specially for CSEC students)

Formulae/Equations

Symbols & Units

Ideal Transformer

= power input, W = power output, W = voltage (secondary coil), V = voltage (primary coil), V = number of turns (secondary coil), no units = number of turns (primary coil), no units = current (primary coil), A = current (secondary coil), A

=

=

Atomic Physics Particle Relationship, = + Atomic Representation, Alpha Particle, Beta Particle, Gamma Emission, Half Life, ⁄ - time taken for half of the atoms in a radiating substance to decay. Einstein’s Equation – describing nuclear fusion and fission. Δ =Δ

= nucleon (mass) number = proton (atomic) number = neutron number = representing atom = (Helium Particle) = (Electron) = Gamma Radiation = Energy, J = mass, kg = speed of electromagnetic waves (incl. light)

Abbreviations: fr. – from dir. – direction incl. – including

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